need to check in comming gas pressure to gas valve and check gas pressure leaving valve.. use a manometer for that.:yes:

 

So let me get this straight... when i clock the furnace by the meter, that is actually giving me the outlet flow rate? And you are saying that i need to check the inlet pressure as well, which would have to be done with a manometer? If the problem is that i need the overall flow rate lower, shouldnt the inlet pressure be somewhat irrelevant?

My reasoning being that regardless of what the inlet pressure is, the gas control valve should always be able to adjust it lower than what it is flowing (as long as the gas control valve adjustment screw wasnt already at the maximum adjustment).

Just trying to understand how it all flows.

Some more info on the issue -- after i replaced the gas control valve, my rollout switch keeps tripping and i observe orange/red erratic flames in the burner area. Someone suggested i check the gas pressure, and i discovered it was flowing at 120k instead of the 97k it is supposed to be at.

I'm hoping this is the reason for the red/erratic flames and rollout switch issue.

Compounding the problem is that when i tried to adjust the gas flow by turning the screw, and then reclocking with the meter, it doesnt appear to have any effect on the gasflow. I turned the screw 14 turns counterclockwise (gradually not all at once) and got almost the same reading... then i turned the screw all the way clockwise until it stopped and it still read basically the same (118-120k). This leads me to believe there is an issue with the regulating screw on the gas control valve, unless i am doing something wrong.

Here is a picture of the screw i am adjusting:

http://imgur.com/uy0Xz3L

Thanks!

 

Don't! Call a pro before you get hurt.

 

STOP!!!! Call a professional.

 

what you are doing is dangerous... you can't play with a gas valve like that ...outlet pressure on a valve is 3.5 on a manometer guage.... inlet pressure should be about 7 inches on a manometer. then after gas pressure is set you have to check temp rise on furnace ....:yes:,,,forget about clocking meter as you say ..after you installed the valve this is what needed done to insure proper install..

 

With all due respect, i thought that was pretty much the point of this forum... for DIY'ers to get input from experts, or close enough.

Telling me 'stop' isn't a reason for me to stop, when you aren't telling me what danger i am in by adjusting an adjustable gas valve, of which i am doing on the instruction of the many professionals that have documented how to clock and adjust a gas valve.

Yes i am aware of the explosion/electrocution risk involved in working with a gas furnace, but again, im not sure how my adjusting of the adjustable control has elicited such a 'stop' response instead of a discussion of what i thought were educated questions about the situation.

I assume it is because i said how many times i turned the screw... but again, that wasn't all at once... i would only turn it once or twice at a time, and i had the unit and gas shut off each time i opened the panel to adjust it, after which i would replace the panel and re clock it.

I dont understand why clocking the meter isn't useful here... doesn't that indicate that the gas flow is incorrect?

 

again with all respect...if a professional told you to adjust a manifold pressure setting with out proper equiptment when doing so ..is just plain wrong....you need to understand how a furnace operates before you start making critial adjustments..

 

Iam inline to agree with the others here call a pro to reset your manifold pressure and then recheck your temp rise to be sure your not overheating the furnace.....

 

On the Plate that gives you the BTU rating of the furnace Also has a spot that will say Minimum and Maximun Gas Supply Pressure. Also on the plate is a box that says Manifold Pressure. You need a Manometer to check pressures and properly adjust the valve.

Sort of like blowing up a tire without a gauge at some point the tire will have air in it but you have no idea of what the pressure is. This is the same thing to little or to much pressure is a very bad thing.

So you have options, Get a Manometer learn howto use it or Hire someone to check and adjust the Valve. You may have other problems other than the gas valve.

 

So you have options, Get a Manometer learn howto use it or Hire someone to check and adjust the Valve. You may have other problems other than the gas valve.

Mmm, well if it came down to it i would definitely buy a manometer before calling a technician... i'm just trying to see if its possible to troubleshoot this issue without one first. Thanks for the input.

How old is this furnace? Are you sure the heat exchanger is ok? Why was the gas valve replaced?
You need to know manifold pressure when doing any adjustments to the burner. You also need to know the delta T over the furnace to understand if its overfiring.

21 years old Rheem RRGG-10E37JKR.

Gas valve was replaced because the furnace wouldn't light. With the help of others and some internet research i used a multimeter to test components that pointed to the gas valve as the culprit. Ordered a used one and the furnace worked again, but with the rollout switch/orange flame issue that i described above.

While replacing the valve i found a large crack in one of the heat exchangers. I dismantled the entire unit and removed all 4 exchanger cells to inspect. 1 was cracked, the rest appeared okay. Replaced the cracked cell and reinstalled/sealed everything.

Thanks for the input.

Meter clocking will tell you how much it is firng. Was there any other appliances running at the same time ie: water heater, clothes dryer, range? Those can screw up your readings.

Is that a new valve or some used item you got from EZ Bay? Don't look new to me. If it is used it may be damaged and you are wasting your time. You cannot adjust a gas valve down or up very far and certainly not as much as your over fired readings indicate.

The proper procedure is to use a manometer to set it but in theory meter clocking will tell you the firing rate. It is NOT the proper way to adjust the valve or a shortcut.

Did you use the proper meter clocking chart and dial and scale. It is easy to make a mistake. You also need to be very accurate with the # of seconds and use a digital watch or stopwatch. I usually do 3 tests and average them.

Great input here, thanks!

There were no other applications using gas. Yes i did 3 runs each time with a digital stopwatch, and averaged them... and then double checked my calculations. All of my readings were 118-120k no matter which way i adjusted the screw.

Yes, the valve was purchased used and i was afraid that that might be the issue as i thought i should be able to see some fluctuation as i adjusted the pressure. I guess i should have been more direct with my initial question, because i guess what i ultimately need to know is whether or not the pressure adjustment is broken on this valve. It seems that it is to me. I was still in troubleshooting mode, though, and just wanted a quick answer about the reducing pressure thing and wanted to keep it brief... whoops. :whistling2:

Thanks again for the input everyone.

edit: and if this discussion is beyond the scope of what this forum is intended for, just let me know. no worries.

 

Don't f with gas. The appliance needs to be set up and checked with combustion analyzer. A heat exchanger inspection is a good idea based upon it being over fired. Just don't want to have a preventable health emergency

 

How old is this furnace? Are you sure the heat exchanger is ok? Why was the gas valve replaced?
You need to know manifold pressure when doing any adjustments to the burner. You also need to know the delta T over the furnace to understand if its overfiring.

 

Meter clocking will tell you how much it is firng. Was there any other appliances running at the same time ie: water heater, clothes dryer, range? Those can screw up your readings.

Is that a new valve or some used item you got from EZ Bay? Don't look new to me. If it is used it may be damaged and you are wasting your time. You cannot adjust a gas valve down or up very far and certainly not as much as your over fired readings indicate.

The proper procedure is to use a manometer to set it but in theory meter clocking will tell you the firing rate. It is NOT the proper way to adjust the valve or a shortcut.

Did you use the proper meter clocking chart and dial and scale. It is easy to make a mistake. You also need to be very accurate with the # of seconds and use a digital watch or stopwatch. I usually do 3 tests and average them.

 

Can this manometer be used also for measuring the manifold pressure or In/Out pressure for the valve ?
http://www.ebay.ca/itm/Digital-Manometer-Differential-Air-Pressure-Meter-Gauge-/120658272340

I guess that the metal piece that is in this picture gets attached to the valve

 

I did the same thing (adjusted the pressure) on the line using the gas line valve. The furnace was short cycling. I still believe that I have a high pressure, I am going to clock it this weekend and measure it when I get my manometer..
From my experience, the line gas valve is a sort of on/off for the most part of the rotation of the screw. It gets to adjust the pressure when it gets very close to off.
I have to admit that I was afraid of playing with the gas valve without having a manometer.

PS: my furnace is also 25 years old.

 

Used valve. While it may have been sold as a good natural gas valve. No way to know if it isn't defective. Or it may have been converted to LP. And you can't adjust an LP converted gas valve low enough for nat gas. It would need to be converted back to a nat gas valve. Which is basically, installing a nat gas spring under the adjusting screw you have been turning.

 

If it was used it may be set for Propane OR somebody screwed the pressure regulator all the way down and it is stuck there wide open. Even though the screw backs up it does not mean the regulator is moving with it. Get a NEW valve.

 

OK, thanks for the advice!

 

I was not saying meter clocking was wrong ...I said forget about it because you were messing up the setting of your gas valve by just turning the manifold set screw without a proper meter... this is a diy site you can do what you like ...just don't expect everyone to react the same way...good luck

 

You said it was wrong to adjust the gas pressure by clocking the meter.

That contradicts the official documentation that i received with my valve, as well as many other sources... which confused me at first.

As far as i can tell it is a valid method, just not the most accurate.

I said forget about it because you were messing up the setting of your gas valve by just turning the manifold set screw without a proper meter

As far as i know, adjusting an adjustable component isn't messing anything up... it's changing whatever you are adjusting.

 

You said it was wrong to adjust the gas pressure by clocking the meter.

That contradicts the official documentation that i received with my valve, as well as many other sources... which confused me at first.

As far as i can tell it is a valid method, just not the most accurate.



As far as i know, adjusting an adjustable component isn't messing anything up... it's changing whatever you are adjusting.

you are wrong. It's messing somebody's income by not getting paid to do a simple thing

As I explaine d you if you go to other forums and you ask that they will declare emergency state, close your thread and scare you to death that you ask an unforgivable thing!

 

Get your hands on this book:
Forced Hot Air Furnaces Troubleshooting and Repair 1999
It has all you need for simple situations and more

 

Now you are confusing me again.

I did not say it was wrong...the way you were adjusting the manifold pressure was wrong..hvac 101 gas pressures are set and checked with a manometer..

When you say 'adjusting the manifold pressure' are you referring to adjusting the flow rate through the gas control valve? Because that is the only thing i did, and you told me the method i used was wrong.

If you think what i did was wrong, you should get in touch with the Honeywell people and tell them their manual is incorrect.

Beyond that, it might be less confusing if you explained WHY you feel it is wrong instead of just saying 'do it this way, the other way is wrong'... especially when the manufacturer instructions contradict what you are saying.

you don't just start turning screws

Right, that's why the very first thing i said was that i measured the gas flow and it was too high.

 

Now you are confusing me again.

When you say 'adjusting the manifold pressure' are you referring to adjusting the flow rate through the gas control valve? Because that is the only thing i did, and you told me the method i used was wrong.

If you think what i did was wrong, you should get in touch with the Honeywell people and tell them their manual is incorrect.

Beyond that, it might be less confusing if you explained WHY you feel it is wrong instead of just saying 'do it this way, the other way is wrong'... especially when the manufacturer instructions contradict what you are saying.


Right, that's why the very first thing i said was that i measured the gas flow and it was too high.

Do you know how many BTUs per cubic foot of gas your nat gas is? You would need to call your gas supplier and ask them.

If its 1000BTU per cf. Clocking the meter will be close. If its 875BTU per CF, then clocking the meter will have your furnace under firing. And if its 1125BTU per CF, clocking the meter will have your furnace over fired. Look at your gas bill. It should tell you BTU content, or caloric content. And show if you need to use multipliers.

Proper set up would be done with a manometer and a combustion analyzer.

 

Yes i checked on my specific BTU rate, thanks.

Since no one can tell me why it's wrong to adjust manifold pressure by clocking the gas meter, i have to assume it's a valid method.

From what i've read, it appears that a manometer would be required if you wanted to verify the inlet pressure... but for the purpose of this discussion (determining firing rate, adjusting gas pressure, determining if the pressure regulator works), that is essentially irrelevant.

In other words:

Is it wrong to install a gas control valve and not check the inlet pressure? Yes.

Is it wrong to adjust manifold pressure by clocking the meter? NO.

 

Its yes to both.

 

You set the manifold pressure with a manometer and check the inlet pressure with it. Inlet pressure is controlled by the gas co regulator and we don't adjust it, just check it.

You can get the firing rate by meter clocking but who they heck is going to run outside and clock the meter and run inside and turn the screw 1/16 of a turn which is how precise you have to be. Then run outside and do the procedure 10-20X.

Totally impractical. Do-able yes. You can get wifey to clock the meter and you tweak the valve and use cell phones or yell. Pros have their ways and it needs to be practical and finely adjusted ( the valve ). Honeywell gives generic advice and is not in the eductaion biz of the trade. They sell parts. In school we are taught to use a manometer and how to finely adjust a valve and pressure. Then there are sealed combustion furnaces and meter clocking won't work very well but that is a whole other technical topic.

Feel free to meter clock it with a new valve. Chances are VERY good it will be set at 3.5"WC from the factory and you are Golden.:yes:

 

Totally impractical. Do-able yes.

Yes but impractical does not mean wrong, or necessarily dangerous. Being told it was wrong/dangerous didnt agree with what i thought i knew about the process, and made things more confusing.

I tried asking clarifying questions in post 3, but i mostly got 'stop' or 'thats wrong do it this way' (although eventually the posts were more substantive) , which didnt help me to understand the issue better. Also, there seems to have been a bit of intertwining between the questions 'can you install a gas valve without a monometer' and 'can you check and adjust gas pressure without a monometer' which muddled things more.

I now know (i think) that the specific reason a monometer would be required in this situation would be to ensure that the pressure being delivered to the valve wasn't too high... which could damage the valve or create errors. That being said, clocking the meter is a legitimate, albeit impractical, way to check/adjust gas pressure.

Also, in Honeywell's defense they state that the inlet pressure should be checked, which would require a monometer... but they also say clocking the meter is acceptable to check/adjust the gas pressure.

You can get the firing rate by meter clocking but who the heck is going to run outside and clock the meter and run inside and turn the screw 1/16 of a turn which is how precise you have to be. Then run outside and do the procedure 10-20X.

:cowboy: Howdy.

In my defense the unit is outside so i didnt have to go very far... heck it only took me about 30 minutes to get 3 or 4 readings. :001_tongue:

Thanks for your input, ive learned a lot more about the process now thanks to some research and the posts here, and im looking forward to checking things out with a new valve.

Thanks again to everyone, including ben's plumbing.

 

Sometimes you have to sift thru the chaff to get the grain or some wise old saying like that.

Feel free to come back.:yes:

 

What you need to know about HVAC or other sites ( Elec or Plumbiing etc ) that have Pros is that there is a purist mentality or attitude and we also like to impress each other with tech talk etc etc. Kinda like bragging or who can talk more technical than the other guy. One upmanship. Nothing wrong with that as it gets boring answering the same clean your flame sensor questions etc etc. There is nothing wrong with what you are doing. I can get into the specifics of combustion analysis but like you said that is not what you are asking and VERY few techs do it anyway. It is more for larger Commercial/Industrial units. Costs many thousands of $$ for the equipment plus it needs periodic calibrating etc so most techs cannot afford it.

Gas burners these days don't have adjustable air shutters on the burners and there is not much you can adjust. With old school burners you had adjustments and especially with conversion burners or oil burners. Like having fuel injection nowadays instead of carbeurators that needed setting. Furnaces burn a lot cleaner due to the improvements in technology.

It is more important to have new good quality CO detectors in your house and check the heat exchanger than worrying about combustion analysis IMO.

Adjusting flow rate is to make sure it is not overfired/overheating or underfired. Combustion analysis and heat output or efficiency is a whole different topic.

Relax. You are fine.

 

they can try to discourage if they wish...imo..as they talk in circles you begin to see they are confused and really don't know the basics of certian things needed to perform the task they are asking questions about.....for that reason ..it is why we tell them to call a pro.....

 

they can try to discourage if they wish...imo..as they talk in circles you begin to see they are confused and really don't know the basics of certian things needed to perform the task they are asking questions about.....for that reason ..it is why we tell them to call a pro.....tireshark...let it go now ...we don't have to prove you wrong....you did that all by yourself.....Iam done with this post...

Dont be a jerk man. The whole reason this thread is like this is because of you telling me what i was doing was wrong, and then proceeding to throw around specific terminology loosely.

Heck, the very first post i made was only asking which way the screw needed to be turned to reduce the firing rate, as i wanted to doublecheck my understanding of what the manual said... all that required was a yes or no and i would have been out of here... but you took the discussion in a different direction by answering questions i didnt ask.

I havent talked in circles, ive been pretty specific about what i was doing since the first post... but now it looks like i am snarky and talking in circles only because i mixed up some terms (because you were using them), and because i wanted to find out the reasons for why what i was doing was 'wrong and dangerous'.

As i said before, i know your intention is to help and that you are only looking out for the safety of DIY'ers... but this isn't just a matter of me trying to be right or wrong.


@ Bob: Thanks for the info. I plan on getting a new valve soon.